CoreInk display fades after some time in use about m5unified

[lovyan03]

M5.Display.powerSaveOn() should do the same as powerHVON() in the CoreInk library.
However, it does not include a delay.
Hence, you may want to wait a few seconds after executing M5.Display.powerSaveOn() before turning off the power.

[lovyan03]

Hello, @patfelst . Thanks for letting me know.
Perhaps executing the following command before going to sleep will solve the problem.

M5.Display.powerSaveOn();

[patfelst]

Thanks just tried but it doesn't seem to make any difference, but I think my current problem is I cannot turn off the CoreInk properly to reset the display. As far as I can tell M5.Power.powerOff() puts the device in deep sleep (I might be wrong) and pressing reset button on back of CoreInk just, well, resets it.

[lovyan03]

The M5.Power.powerOff() function operates to turn off power by setting the power hold pin LOW.
CoreInk is deepSleep because the power does not turn off while USB power is being supplied due to circuit specifications.
If the USB is not connected, the power should turn off.

[patfelst]

thanks yes that works to power down the device - ie remove USB power and .powerOff()

I'm not sure what fixed it but I did the following and it looks ok again now:

• added M5.Display.powerSaveOn() before entering deep sleep
• changed the display rotation
• played with turning the CoreInk power off (I don't think this played a part now)
• changed display mode from M5.Display.setEpdMode(epd_mode_t::epd_text) to M5.Display.setEpdMode(epd_mode_t::epd_fast)
  
  

Before I close, what does M5.Display.powerSaveOn() actually do?

Thanks for your help!